1. Field of the Invention
The present invention generally relates to devices for configuring physical projections. More particularly, the present invention relates to a method and apparatus which is especially useful for straightening an array of pins such as the numerous electrical connection pins on an integrated circuit mounting package.
2. Description of the Related Art
Electrical connectors generally comprise a plug, having a plurality of connector pins, and a jack, having a matching number of sockets, for mating with the plug. From the simple two or three-pronged household plug to multipinned computer connectors, most coupling arrangements suffer from the same problem: if one or more of the pins are not aligned to a specific tolerance, proper mating cannot be achieved. An attempt at mating a plug with a bent pin results not only in a faulty electrical connection, but often in irreparable damage to the plug. Generally, this tolerance is defined by the planar alignment and relative oversize of the sockets with respect to the pins.
The problem increases in complexity with the increase in the number, the increase in density, and the decrease in size of the pins.
For example, for integrated circuit (IC) devices, several different types of mounting packages exist in today's technology. A commonly used dual-in-line (DIP) IC mounting package 2 is shown in FIG. 1 (magnified to a scale of approximately 1.5 actual size). Twenty-eight electrical connector pins 4 project from the base 6 of the package 2. Insertion of this type of package 2 into a plug poses little problem. Proper mating of the pins and sockets can be visually verified. However, if insertion is done by robotics, a bent pin 4 could cause problems.
Shown in FIG. 2 is a typical IC mounting package 3 for a gate array integrated circuit (also magnified by approximately 1.5 times actual size). Because of the nature of the circuitry involved, there are 144 pins 4 protruding from the base 6 of this exemplary package 3. When inserting this type of package 3 into a plug, verification of proper alignment of the pins 4 and their mating sockets is obviously a much more difficult task.
With a package such as shown in FIG. 1, realignment of a bent pin 4 may be possible as long as the internal electrical coupling of the IC to the bent pin was not broken during a misaligned mating attempt. However, because of the size and arrangement of the pins 4 on the package 3 of FIG. 2, a bent-pin misaligned insertion into a socket would most likely form an electrical short to an adjacent pin. Activation of the IC would most likely result in irreparable damage to the circuitry. Even if the circuitry remained undamaged, because of the more fragile nature of this type of pin, a later attempt to mechanically straighten the offending pin usually will result in its breaking off. Moreover, because of the pin density on this type of package 3, the very same attempt at straightening one pin could result in the bending out of tolerance of adjacent pins.
One known method and apparatus for straightening IC pins is a model 1060 sold under the trademark LEADSTAR and manufactured by Alpha Modular Systems, Oceanside, Calif. In this system, the pins are combed and vibrated to a tolerance of approximately the width of one pin. For a very dense pin configuration, such a tolerance may be inadequate.
Hence, there is a need for a method and apparatus for straightening an array of pins to a predetermined specific alignment tolerance.